Working just fine here...very simple..
1) Export from VegasPro through the Mpeg2 template for Blu-ray authoring...export audio as AC3

2) Create a BLU_RAY PROJECT in DVDAPRO - not a DVD Project!

3) Burn with a Blu-Ray BURNER on Blu-Ray Media.
Kapow ! DONE!

I did exactly what you said but the rendered file (m2v) shows up in the DVDA "Explorer" tab with the following message below it: "Information unavailable. Media must be prepared for open." When I attempt to drag the file to the menu, it never registers. The file is just under two hours. I ran a test in which I rendered a few minutes of the video (loop region) and was successful with it but when I render the entire document it doesn't work! Help!

You say the file is two (2) hours...what does that mean?
What time reference is at the end of your VegasPro Timeline indicating runtime of the track/project ?

Two hours is just to much if that's what you are indicating. Select only the first half of your timeline for render to Blu-Ray media stream for video and audio files... This will create a shorter Blu-Ray feature that you will burn to Disk 1, perhaps of a two-disk set.

You certainly need to be sure that your total file size does not exceed the format, so must choose an appropriate bit rate.

Although I have only done this a couple of times in 11, I have found that using the Main Concept constant bit rate at 25megs seems to work well....plus doing the audio separately.......The Vegas manual claims 35megs as doable, but DVDA would not accept that when I tried. In fact, the tables in the Vegas 11 and DVDA manuals seemed to be somewhat off the mark about what works.

My project is derived mostly from HDV footage (FX1) at 1440x1080. I am currently doing some testing to see what happens when I render at 1920x1080 since I did not take good notes last time I tried this (deadline, in too much of a hurry), but my memory says there was not much if any visible difference in the final BluRay.......but I simply cannot remember which I used in the end.

I could not bring the Main Concept renders into the Vegas timeline, but they can be auditioned on the DVDA timeline.

I would also add that you can do other options than those suggested in the article....for instance, you can choose 24bit .wav stream for the audio, a lower bit rate for the video.....or some other encoders. But the Main Concept at 25mbs should work unless the resultant file is too large.

You also do not need to name the audio and video files the same. Whatever the names, they can just be dragged onto the DVDA timeline.

You may be on to something. When I originally rendered the file (about 21GB file size, 1:40 on the timeline) I used the "match project" settings, but was unable to access the m2v file in Architect, yet when I rendered a few minutes of the file using the same settings, I was able to capture the result in Architect.

I printed the "Render Settings for Blu-ray Disc" document which suggests using the Blu-ray 1920x1080 60i render settings. That doesn't match my project but I'll give it a try and see what happens. Takes about an hour to render the entire project...

Followed the 1920-1080 60i render settings described in the "Render Settings for Blu-ray" document and only rendered one hour of video. Still didn't work in Architect and continue to get the "information unavailable. Media must be prepared for open" message.

Any other ideas?

Are you rendering the audio separately? This seems to be required for completing this task.

Even at that, you have to make sure that your total, combined files are under 25gigs......I am not sure how far under at this point, but it certainly needs to be under unless you have a dual layer disk.

I am just doing another series of tests on my HDV trailer with some edits, and preparing both a 1440x and 1920x rendered BluRay version.

You must, if you have not been doing this, choose BluRay for the DVDA project, as well as set up the audio and video parameters.....perhaps if you did not do that, the file perhaps would not be accepted.

My tests at both formats have worked prior to today......however, I am discovering further menus in DVDA that require attention if you want to really maximize your quality and/or fit everything on the disk......It seems that simply setting the DVDA project properties up does not determine the end bit rates that will burn, and DVDA sometimes warns you and sometimes does not about quality changes that will occur (in audio or video)......so it makes sense to go through the full properties menu that lives inside the burning menu.....once you get there.

It now seems possible to me that I could have made some higher video bit rates burn for this trailer......and I will have to test it to see.

Perhaps while I do my tests.....which will take some time....you could double check all your settings in DVDA........like I said, I had no problem burning a BluRay at 1440x1080 60i, but I set the DVDA project up for that.......The first time around I stuck with the inferior 16bit PCM audio because it is a default, but have successfully changed to 24bit this time around, and the burn is proceeding as we speak.

To reiterate, start with a fresh DVDA project, make it BluRay, and match all the parameters of your rendered files.

More test results:

Even after moving all the parameters (in the DVDA burning Optimize menu) up to match the full bit rates of the files (cbr25mbs, 48k 24bit PCM), the burning menu indicates that I could have gotten 100 minutes of this stuff on BluRay......so reducing your bit rate to 18mbs, which seems to be the default in this menu, would easily give you your 2 hours.

What appears to be happening in this Optimize menu is that you set up additional compression as needed to fit everything on the disk.

More later.

You've been incredibly helpful in trying to resolve this problem! I just got off the phone with Sony. They had me uninstall DVDA, then reinstall it, and amazingly it worked! Not sure what the problem was but regardless, it's solved.

Many, many thanks for your kind efforts!